电场调控与RESURF-台面结构侧壁漏电流抑制实现高性能Ga₂O₃功率器件

This work demonstrates high-performance vertical -Ga _ {2} O _ {3} rectifiers featuring a reduced-surface-field mesa (RESURF-mesa) structure. This RESURF-mesa design employs nonself-aligned etching to form a 5- m deep mesa, utilizing a 5- m-thick SiO _ {2} layer and 120-nm p-type nickel oxide (NiO) to encapsulate the sidewalls with an argon-to-oxygen flux ratio of 20:1. Technology computer-aided design (TCAD) simulations confirm a reduced surface electric field (E-field) with an optimized NiO thickness. Consequently, the RESURF-mesa Schottky barrier diode (SBD) with 120-nm NiO exhibits a breakdown voltage (BV) of 2600 V, while the RESURF-mesa heterojunction diode (HJD) sustains a reverse voltage exceeding 3000 V due to the stronger heterointerface. The specific on-resistance ( {R} _ {ON, {sp}} ) of both devices is 4.1 m cm ^ {2} , yielding the power figure of merit (PFOM) of 1.6 GW/cm ^ {2} for RESURF-mesa SBD and 2.2 GW/cm ^ {2} for RESURF-mesa HJD. The performance of both rectifiers is among the highest in reported multikilovolts Ga _ {2} O _ {3} SBDs and HJDs. Additionally, we have investigated the origin of sidewall leakage current and developed methods to suppress it, which is also effective at high temperatures. These findings underscore the significant potential of RESURF-mesa technology in advancing multikilovolt Ga _ {2} O _ {3} device applications.